关键词: 图像检索, 颜色直方图, 基元梯度方向共生直方图, 视觉均衡基元, 视觉非均衡基元

Abstract: In order to fuse shape and color features, this paper presents a novel color image retrieval algorithm based on motif gradient direction co-occurrence histogram and color histogram. Firstly, divide the image into 4×4 non-overlapping motif. Based on the average amplitude of the gradient, each motif is classified into visual uniform motif and visual non-uniform motif. Secondly, calculate average color during each visual uniform motif, and quantify it into 72 levels in HSV space. Construct the visual uniform motif color histogram as the local color image descriptors. Then, obtain the global color histogram by uniformly quantize the HSV color image into 72 colors. Lastly, obtain the motif gradient direction co-occurrence histogram to depict the shape feature of image. A color image retrieval feature vector is fused by the local color image descriptor, the global color histogram and the shape feature. Experimental results indicate that the algorithm can describe the color and shape feature, and it has invariance in rotation and size. Its similarity measure is very effective, and it has higher precision and recall rate.

Key words: image retrieval, color histogram, motif gradient direction co-occurrence histogram, visual uniform motif, visual non-uniform motif